Fire dampers are known in the art. For example, fire dampers and ceiling radiation dampers (collectively and broadly referred herein to as “fire damper”) which are “dynamic” and “standard” are known and require periodic testing according to some code requirements to ensure their proper operation. In some applications, these dampers cannot be used due to products or byproducts in the air stream which will cause build up and create a hazard of blockage or possibly negatively impair the proper operation of the damper. When these fire dampers are concealed within a fire rated assembly, access is required to the damper requiring a fire rated access door. Such dampers are usually not suitable for use in small ductwork including kitchen exhaust, dryer exhaust, bathroom ventilation and any other ductwork which may require material collection such as in a shop having substantial dust of material build up.
Additionally, fire dampers using a fusible link are known in the art. For example, Aire Technologies Inc. makes a fire damper “Series 65 Type B Static Fire Damper” which includes a rectangular frame having a top enclosure having blades riveted to the frame and held in place by a fusible link which will release the blades to cut off circulation in the duct upon reaching a certain temperature. Such devices while useful for certain applications are complex, expensive and do not readily lend themselves to use in ductwork of smaller applications such as a kitchen exhaust, dryer exhaust or the like.
Additionally, fire dampers using an intumescent are known in the art. However, these fire dampers are complex and expensive to manufacture.
These devices while useful in certain situations have various shortcomings including their complex nature, their expense to manufacture and their inability to work well in small ductwork or ventilation systems. These and other shortcomings of such devices are addressed by the present invention.